Consider

Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
Draw a card.

Mystical Dispute

This spell costs {2} less to cast if it targets a blue spell.
Counter target spell unless its controller pays {3}.

Shivan Reef

{T}: Add {C}.
{T}: Add {U} or {R}. Shivan Reef deals 1 damage to you.

Fiery Impulse

Fiery Impulse deals 2 damage to target creature.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, Fiery Impulse deals 3 damage instead.

Mountain

Crackling Drake

Flying
Crackling Drake's power is equal to the total number of instant and sorcery cards you own in exile and in your graveyard.
When Crackling Drake enters the battlefield, draw a card.

Izzet Charm

Choose one —
• Counter target noncreature spell unless its controller pays {2}.
• Izzet Charm deals 2 damage to target creature.
• Draw two cards, then discard two cards.

Island

Treasure Cruise

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Draw three cards.

Sleight of Hand

Look at the top two cards of your library. Put one of them into your hand and the other on the bottom of your library.

Sulfur Falls

Sulfur Falls enters the battlefield tapped unless you control an Island or a Mountain.
{T}: Add {U} or {R}.

Chart a Course

Draw two cards. Then discard a card unless you attacked this turn.

Awoken Horror

When this creature transforms into Awoken Horror, return all non-Horror creatures to their owners' hands.

Thing in the Ice

Defender
Thing in the Ice enters the battlefield with four ice counters on it.
Whenever you cast an instant or sorcery spell, remove an ice counter from Thing in the Ice. Then if it has no ice counters on it, transform it.

Thing in the Ice // Awoken Horror

Steam Vents

({T}: Add {U} or {R}.)
As Steam Vents enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Spirebluff Canal

Spirebluff Canal enters the battlefield tapped unless you control two or fewer other lands.
{T}: Add {U} or {R}.

Arclight Phoenix

Flying, haste
At the beginning of combat on your turn, if you've cast three or more instant and sorcery spells this turn, return Arclight Phoenix from your graveyard to the battlefield.

Pieces of the Puzzle

Reveal the top five cards of your library. Put up to two instant and/or sorcery cards from among them into your hand and the rest into your graveyard.

Lightning Axe

As an additional cost to cast this spell, discard a card or pay {5}.
Lightning Axe deals 5 damage to target creature.

Temple of Epiphany

Temple of Epiphany enters the battlefield tapped.
When Temple of Epiphany enters the battlefield, scry 1.
{T}: Add {U} or {R}.